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* Unify SIGHUP handling between normal and walsender backends.Andres Freund2017-06-05
| | | | | | | | | | | | | | | | | | | | Because walsender and normal backends share the same main loop it's problematic to have two different flag variables, set in signal handlers, indicating a pending configuration reload. Only certain walsender commands reach code paths checking for the variable (START_[LOGICAL_]REPLICATION, CREATE_REPLICATION_SLOT ... LOGICAL, notably not base backups). This is a bug present since the introduction of walsender, but has gotten worse in releases since then which allow walsender to do more. A later patch, not slated for v10, will similarly unify SIGHUP handling in other types of processes as well. Author: Petr Jelinek, Andres Freund Reviewed-By: Michael Paquier Discussion: https://postgr.es/m/20170423235941.qosiuoyqprq4nu7v@alap3.anarazel.de Backpatch: 9.2-, bug is present since 9.0
* Fix signal handling in logical replication workersPeter Eisentraut2017-06-02
| | | | | | | | | | The logical replication worker processes now use the normal die() handler for SIGTERM and CHECK_FOR_INTERRUPTS() instead of custom code. One problem before was that the apply worker would not exit promptly when a subscription was dropped, which could lead to deadlocks. Author: Petr Jelinek <petr.jelinek@2ndquadrant.com> Reported-by: Masahiko Sawada <sawada.mshk@gmail.com>
* Improve castNode notation by introducing list-extraction-specific variants.Tom Lane2017-04-10
| | | | | | | | | | | | | | | | | This extends the castNode() notation introduced by commit 5bcab1114 to provide, in one step, extraction of a list cell's pointer and coercion to a concrete node type. For example, "lfirst_node(Foo, lc)" is the same as "castNode(Foo, lfirst(lc))". Almost half of the uses of castNode that have appeared so far include a list extraction call, so this is pretty widely useful, and it saves a few more keystrokes compared to the old way. As with the previous patch, back-patch the addition of these macros to pg_list.h, so that the notation will be available when back-patching. Patch by me, after an idea of Andrew Gierth's. Discussion: https://postgr.es/m/14197.1491841216@sss.pgh.pa.us
* Remove dead code and fix comments in fast-path function handling.Heikki Linnakangas2017-04-06
| | | | | | | | | | | | | | | | HandleFunctionRequest() is no longer responsible for reading the protocol message from the client, since commit 2b3a8b20c2. Fix the outdated comments. HandleFunctionRequest() now always returns 0, because the code that used to return EOF was moved in 2b3a8b20c2. Therefore, the caller no longer needs to check the return value. Reported by Andres Freund. Backpatch to all supported versions, even though this doesn't have any user-visible effect, to make backporting future patches in this area easier. Discussion: https://www.postgresql.org/message-id/20170405010525.rt5azbya5fkbhvrx@alap3.anarazel.de
* Fix two undocumented parameters to functions from ENR patch.Kevin Grittner2017-04-01
| | | | | | | | | | | | On ProcessUtility document the parameter, to match others. On CreateCachedPlan drop the queryEnv parameter. It was not referenced within the function, and had been added on the assumption that with some unknown future usage of QueryEnvironment it might be useful to do something there. We have avoided other "just in case" implementation of unused paramters, so drop it here. Per gripe from Tom Lane
* Add infrastructure to support EphemeralNamedRelation references.Kevin Grittner2017-03-31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A QueryEnvironment concept is added, which allows new types of objects to be passed into queries from parsing on through execution. At this point, the only thing implemented is a collection of EphemeralNamedRelation objects -- relations which can be referenced by name in queries, but do not exist in the catalogs. The only type of ENR implemented is NamedTuplestore, but provision is made to add more types fairly easily. An ENR can carry its own TupleDesc or reference a relation in the catalogs by relid. Although these features can be used without SPI, convenience functions are added to SPI so that ENRs can easily be used by code run through SPI. The initial use of all this is going to be transition tables in AFTER triggers, but that will be added to each PL as a separate commit. An incidental effect of this patch is to produce a more informative error message if an attempt is made to modify the contents of a CTE from a referencing DML statement. No tests previously covered that possibility, so one is added. Kevin Grittner and Thomas Munro Reviewed by Heikki Linnakangas, David Fetter, and Thomas Munro with valuable comments and suggestions from many others
* Cast result of copyObject() to correct typePeter Eisentraut2017-03-28
| | | | | | | | | | | | | | copyObject() is declared to return void *, which allows easily assigning the result independent of the input, but it loses all type checking. If the compiler supports typeof or something similar, cast the result to the input type. This creates a greater amount of type safety. In some cases, where the result is assigned to a generic type such as Node * or Expr *, new casts are now necessary, but in general casts are now unnecessary in the normal case and indicate that something unusual is happening. Reviewed-by: Mark Dilger <hornschnorter@gmail.com>
* Allow for parallel execution whenever ExecutorRun() is done only once.Robert Haas2017-03-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Previously, it was unsafe to execute a plan in parallel if ExecutorRun() might be called with a non-zero row count. However, it's quite easy to fix things up so that we can support that case, provided that it is known that we will never call ExecutorRun() a second time for the same QueryDesc. Add infrastructure to signal this, and cross-checks to make sure that a caller who claims this is true doesn't later reneg. While that pattern never happens with queries received directly from a client -- there's no way to know whether multiple Execute messages will be sent unless the first one requests all the rows -- it's pretty common for queries originating from procedural languages, which often limit the result to a single tuple or to a user-specified number of tuples. This commit doesn't actually enable parallelism in any additional cases, because currently none of the places that would be able to benefit from this infrastructure pass CURSOR_OPT_PARALLEL_OK in the first place, but it makes it much more palatable to pass CURSOR_OPT_PARALLEL_OK in places where we currently don't, because it eliminates some cases where we'd end up having to run the parallel plan serially. Patch by me, based on some ideas from Rafia Sabih and corrected by Rafia Sabih based on feedback from Dilip Kumar and myself. Discussion: http://postgr.es/m/CA+TgmobXEhvHbJtWDuPZM9bVSLiTj-kShxQJ2uM5GPDze9fRYA@mail.gmail.com
* Logical replication support for initial data copyPeter Eisentraut2017-03-23
| | | | | | | | | | | | | | | | | | | | | | | Add functionality for a new subscription to copy the initial data in the tables and then sync with the ongoing apply process. For the copying, add a new internal COPY option to have the COPY source data provided by a callback function. The initial data copy works on the subscriber by receiving COPY data from the publisher and then providing it locally into a COPY that writes to the destination table. A WAL receiver can now execute full SQL commands. This is used here to obtain information about tables and publications. Several new options were added to CREATE and ALTER SUBSCRIPTION to control whether and when initial table syncing happens. Change pg_dump option --no-create-subscription-slots to --no-subscription-connect and use the new CREATE SUBSCRIPTION ... NOCONNECT option for that. Author: Petr Jelinek <petr.jelinek@2ndquadrant.com> Tested-by: Erik Rijkers <er@xs4all.nl>
* Use castNode() in a bunch of statement-list-related code.Tom Lane2017-01-26
| | | | | | | | | | | | | When I wrote commit ab1f0c822, I really missed the castNode() macro that Peter E. had proposed shortly before. This back-fills the uses I would have put it to. It's probably not all that significant, but there are more assertions here than there were before, and conceivably they will help catch any bugs associated with those representation changes. I left behind a number of usages like "(Query *) copyObject(query_var)". Those could have been converted as well, but Peter has proposed another notational improvement that would handle copyObject cases automatically, so I let that be for now.
* Add castNode(type, ptr) for safe casting between NodeTag based types.Andres Freund2017-01-26
| | | | | | | | | | | | | | | | | | | | | | | | The new function allows to cast from one NodeTag based type to another, while asserting that the conversion is valid. This replaces the common pattern of doing a cast and a Assert(IsA(ptr, type)) close-by. As this seems likely to be used pervasively, we decided to backpatch this change the addition of this macro. Otherwise backpatched fixes are more likely not to work on back-branches. On branches before 9.6, where we do not yet rely on inline functions being available, the type assertion is only performed if PG_USE_INLINE support is detected. The cast obviously is performed regardless. For the benefit of verifying the macro compiles in the back-branches, this commit contains a single use of the new macro. On master, a somewhat larger conversion will be committed separately. Author: Peter Eisentraut and Andres Freund Reviewed-By: Tom Lane Discussion: https://postgr.es/m/c5d387d9-3440-f5e0-f9d4-71d53b9fbe52@2ndquadrant.com Backpatch: 9.2-
* Avoid core dump for empty prepared statement in an aborted transaction.Tom Lane2017-01-19
| | | | | | | | | | | | Brown-paper-bag bug in commit ab1f0c822: the old code here coped with null CachedPlanSource.raw_parse_tree, the new code not so much. Per report from Dave Cramer. No regression test, because our core testing infrastructure doesn't provide any easy way to exercise this path. Fortunately, the JDBC crew test it regularly. Discussion: https://postgr.es/m/CADK3HH+Ug3xCysKqw_dZOnaNnytZ1Rh5yP05hjO-e4NoyRxVvA@mail.gmail.com
* Change representation of statement lists, and add statement location info.Tom Lane2017-01-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch makes several changes that improve the consistency of representation of lists of statements. It's always been the case that the output of parse analysis is a list of Query nodes, whatever the types of the individual statements in the list. This patch brings similar consistency to the outputs of raw parsing and planning steps: * The output of raw parsing is now always a list of RawStmt nodes; the statement-type-dependent nodes are one level down from that. * The output of pg_plan_queries() is now always a list of PlannedStmt nodes, even for utility statements. In the case of a utility statement, "planning" just consists of wrapping a CMD_UTILITY PlannedStmt around the utility node. This list representation is now used in Portal and CachedPlan plan lists, replacing the former convention of intermixing PlannedStmts with bare utility-statement nodes. Now, every list of statements has a consistent head-node type depending on how far along it is in processing. This allows changing many places that formerly used generic "Node *" pointers to use a more specific pointer type, thus reducing the number of IsA() tests and casts needed, as well as improving code clarity. Also, the post-parse-analysis representation of DECLARE CURSOR is changed so that it looks more like EXPLAIN, PREPARE, etc. That is, the contained SELECT remains a child of the DeclareCursorStmt rather than getting flipped around to be the other way. It's now true for both Query and PlannedStmt that utilityStmt is non-null if and only if commandType is CMD_UTILITY. That allows simplifying a lot of places that were testing both fields. (I think some of those were just defensive programming, but in many places, it was actually necessary to avoid confusing DECLARE CURSOR with SELECT.) Because PlannedStmt carries a canSetTag field, we're also able to get rid of some ad-hoc rules about how to reconstruct canSetTag for a bare utility statement; specifically, the assumption that a utility is canSetTag if and only if it's the only one in its list. While I see no near-term need for relaxing that restriction, it's nice to get rid of the ad-hocery. The API of ProcessUtility() is changed so that what it's passed is the wrapper PlannedStmt not just the bare utility statement. This will affect all users of ProcessUtility_hook, but the changes are pretty trivial; see the affected contrib modules for examples of the minimum change needed. (Most compilers should give pointer-type-mismatch warnings for uncorrected code.) There's also a change in the API of ExplainOneQuery_hook, to pass through cursorOptions instead of expecting hook functions to know what to pick. This is needed because of the DECLARE CURSOR changes, but really should have been done in 9.6; it's unlikely that any extant hook functions know about using CURSOR_OPT_PARALLEL_OK. Finally, teach gram.y to save statement boundary locations in RawStmt nodes, and pass those through to Query and PlannedStmt nodes. This allows more intelligent handling of cases where a source query string contains multiple statements. This patch doesn't actually do anything with the information, but a follow-on patch will. (Passing this information through cleanly is the true motivation for these changes; while I think this is all good cleanup, it's unlikely we'd have bothered without this end goal.) catversion bump because addition of location fields to struct Query affects stored rules. This patch is by me, but it owes a good deal to Fabien Coelho who did a lot of preliminary work on the problem, and also reviewed the patch. Discussion: https://postgr.es/m/alpine.DEB.2.20.1612200926310.29821@lancre
* Update copyright via script for 2017Bruce Momjian2017-01-03
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* Add support for temporary replication slotsPeter Eisentraut2016-12-12
| | | | | | | This allows creating temporary replication slots that are removed automatically at the end of the session or on error. From: Petr Jelinek <petr.jelinek@2ndquadrant.com>
* Remove or reduce verbosity of some debug messages.Robert Haas2016-11-17
| | | | | | | | | | | | | | | | | | | The debug messages that merely print StartTransactionCommand, CommitTransactionCommand, ProcessUtilty, or ProcessQuery with no additional details seem to be useless. Get rid of them. The transaction status messages produced by ShowTransactionState are occasionally useful, but they are extremely verbose, producing multiple lines of log output every time they fire, which can happens multiple times per transaction. So, reduce the level to DEBUG5; avoid emitting an extra line just to explain which debug point is at issue; and tighten up the rest of the message so it doesn't use quite so much horizontal space. With these changes, it's possible to run a somewhat busy system with a log level even as high as DEBUG4, whereas previously anything above DEBUG2 would flood the log with output that probably wasn't really all that useful.
* Account for catalog snapshot in PGXACT->xmin updates.Tom Lane2016-11-15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The CatalogSnapshot was not plugged into SnapshotResetXmin()'s accounting for whether MyPgXact->xmin could be cleared or advanced. In normal transactions this was masked by the fact that the transaction snapshot would be older, but during backend startup and certain utility commands it was possible to re-use the CatalogSnapshot after MyPgXact->xmin had been cleared, meaning that recently-deleted rows could be pruned even though this snapshot could still see them, causing unexpected catalog lookup failures. This effect appears to be the explanation for a recent failure on buildfarm member piculet. To fix, add the CatalogSnapshot to the RegisteredSnapshots heap whenever it is valid. In the previous logic, it was possible for the CatalogSnapshot to remain valid across waits for client input, but with this change that would mean it delays advance of global xmin in cases where it did not before. To avoid possibly causing new table-bloat problems with clients that sit idle for long intervals, add code to invalidate the CatalogSnapshot before waiting for client input. (When the backend is busy, it's unlikely that the CatalogSnapshot would be the oldest snap for very long, so we don't worry about forcing early invalidation of it otherwise.) In passing, remove the CatalogSnapshotStale flag in favor of using "CatalogSnapshot != NULL" to represent validity, as we do for the other special snapshots in snapmgr.c. And improve some obsolete comments. No regression test because I don't know a deterministic way to cause this failure. But the stress test shown in the original discussion provokes "cache lookup failed for relation 1255" within a few dozen seconds for me. Back-patch to 9.4 where MVCC catalog scans were introduced. (Note: it's quite easy to produce similar failures with the same test case in branches before 9.4. But MVCC catalog scans were supposed to fix that.) Discussion: <16447.1478818294@sss.pgh.pa.us>
* Make getrusage() output a little more readablePeter Eisentraut2016-10-19
| | | | | Reviewed-by: Robert Haas <robertmhaas@gmail.com> Reviewed-by: Peter Geoghegan <pg@heroku.com>
* Drop server support for FE/BE protocol version 1.0.Tom Lane2016-10-11
| | | | | | | | | While this isn't a lot of code, it's been essentially untestable for a very long time, because libpq doesn't support anything older than protocol 2.0, and has not since release 6.3. There's no reason to believe any other client-side code still uses that protocol, either. Discussion: <2661.1475849167@sss.pgh.pa.us>
* Add macros to make AllocSetContextCreate() calls simpler and safer.Tom Lane2016-08-27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I found that half a dozen (nearly 5%) of our AllocSetContextCreate calls had typos in the context-sizing parameters. While none of these led to especially significant problems, they did create minor inefficiencies, and it's now clear that expecting people to copy-and-paste those calls accurately is not a great idea. Let's reduce the risk of future errors by introducing single macros that encapsulate the common use-cases. Three such macros are enough to cover all but two special-purpose contexts; those two calls can be left as-is, I think. While this patch doesn't in itself improve matters for third-party extensions, it doesn't break anything for them either, and they can gradually adopt the simplified notation over time. In passing, change TopMemoryContext to use the default allocation parameters. Formerly it could only be extended 8K at a time. That was probably reasonable when this code was written; but nowadays we create many more contexts than we did then, so that it's not unusual to have a couple hundred K in TopMemoryContext, even without considering various dubious code that sticks other things there. There seems no good reason not to let it use growing blocks like most other contexts. Back-patch to 9.6, mostly because that's still close enough to HEAD that it's easy to do so, and keeping the branches in sync can be expected to avoid some future back-patching pain. The bugs fixed by these changes don't seem to be significant enough to justify fixing them further back. Discussion: <21072.1472321324@sss.pgh.pa.us>
* Revert "Add some temporary code to record stack usage at server process exit."Tom Lane2016-07-10
| | | | | | | This reverts commit 88cf37d2a86d5b66380003d7c3384530e3f91e40 as well as follow-on commits ea9c4a16d5ad88a1d28d43ef458e3209b53eb106 and c57562725d219c4249b82f4a4fb5aaeee3ae0d53. We've learned about as much as we can from the buildfarm.
* Add more temporary code to record stack usage at server process exit.Tom Lane2016-07-08
| | | | | | | | After a look at preliminary results from commit 88cf37d2a86d5b66, I realized it'd be a good idea to spew out the maximum depth measurement seen by check_stack_depth. So add some quick-n-dirty code to do that. Like the previous commit, this will be reverted once we've gathered a set of buildfarm runs with it.
* Be more predictable about reporting "lock timeout" vs "statement timeout".Tom Lane2016-05-27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If both timeout indicators are set when we arrive at ProcessInterrupts, we've historically just reported "lock timeout". However, some buildfarm members have been observed to fail isolationtester's timeouts test by reporting "lock timeout" when the statement timeout was expected to fire first. The cause seems to be that the process is allowed to sleep longer than expected (probably due to heavy machine load) so that the lock timeout happens before we reach the point of reporting the error, and then this arbitrary tiebreak rule does the wrong thing. We can improve matters by comparing the scheduled timeout times to decide which error to report. I had originally proposed greatly reducing the 1-second window between the two timeouts in the test cases. On reflection that is a bad idea, at least for the case where the lock timeout is expected to fire first, because that would assume that it takes negligible time to get from statement start to the beginning of the lock wait. Thus, this patch doesn't completely remove the risk of test failures on slow machines. Empirically, however, the case this handles is the one we are seeing in the buildfarm. The explanation may be that the other case requires the scheduler to take the CPU away from a busy process, whereas the case fixed here only requires the scheduler to not give the CPU back right away to a process that has been woken from a multi-second sleep (and, perhaps, has been swapped out meanwhile). Back-patch to 9.3 where the isolationtester timeouts test was added. Discussion: <8693.1464314819@sss.pgh.pa.us>
* Add idle_in_transaction_session_timeout.Robert Haas2016-03-16
| | | | | Vik Fearing, reviewed by Stéphane Schildknecht and me, and revised slightly by me.
* Enable parallelism for prepared statements and extended query protocol.Robert Haas2016-02-25
| | | | | | | | | | | | | | | | | | Parallel query can't handle running a query only partially rather than to completion. However, there seems to be no way to run a statement prepared via SQL PREPARE other than to completion, so we can enable it there without a problem. The situation is more complicated for the extend query protocol. libpq seems to provide no way to send an Execute message with a non-zero rowcount, but some other client might. If that happens, and a parallel plan was chosen, we'll execute the parallel plan without using any workers, which may be somewhat inefficient but should still work. Hopefully this won't be a problem; users can always set max_parallel_degree=0 to avoid choosing parallel plans in the first place. Amit Kapila, reviewed by me.
* Update copyright for 2016Bruce Momjian2016-01-02
| | | | Backpatch certain files through 9.1
* Adjust behavior of single-user -j mode for better initdb error reporting.Tom Lane2015-12-17
| | | | | | | | | | | | | | | | | | | | | | | | | | Previously, -j caused the entire input file to be read in and executed as a single command string. That's undesirable, not least because any error causes the entire file to be regurgitated as the "failing query". Some experimentation suggests a better rule: end the command string when we see a semicolon immediately followed by two newlines, ie, an empty line after a query. This serves nicely to break up the existing examples such as information_schema.sql and system_views.sql. A limitation is that it's no longer possible to write such a sequence within a string literal or multiline comment in a file meant to be read with -j; but there are no instances of such a problem within the data currently used by initdb. (If someone does make such a mistake in future, it'll be obvious because they'll get an unterminated-literal or unterminated-comment syntax error.) Other than that, there shouldn't be any negative consequences; you're not forced to end statements that way, it's just a better idea in most cases. In passing, remove src/include/tcop/tcopdebug.h, which is dead code because it's not included anywhere, and hasn't been for more than ten years. One of the debug-support symbols it purported to describe has been unreferenced for at least the same amount of time, and the other is removed by this commit on the grounds that it was useless: forcing -j mode all the time would have broken initdb. The lack of complaints about that, or about the missing inclusion, shows that no one has tried to use TCOP_DONTUSENEWLINE in many years.
* Fix problems with ParamListInfo serialization mechanism.Robert Haas2015-11-02
| | | | | | | | | | | | | | | | | | | | | | Commit d1b7c1ffe72e86932b5395f29e006c3f503bc53d introduced a mechanism for serializing a ParamListInfo structure to be passed to a parallel worker. However, this mechanism failed to handle external expanded values, as pointed out by Noah Misch. Repair. Moreover, plpgsql_param_fetch requires adjustment because the serialization mechanism needs it to skip evaluating unused parameters just as we would do when it is called from copyParamList, but params == estate->paramLI in that case. To fix, make the bms_is_member test in that function unconditional. Finally, have setup_param_list set a new ParamListInfo field, paramMask, to the parameters actually used in the expression, so that we don't try to fetch those that are not needed when serializing a parameter list. This isn't necessary for correctness, but it makes the performance of the parallel executor code comparable to what we do for cases involving cursors. Design suggestions and extensive review by Noah Misch. Patch by me.
* Message style improvementsPeter Eisentraut2015-10-28
| | | | | Message style, plurals, quoting, spelling, consistency with similar messages
* Remove set_latch_on_sigusr1 flag.Robert Haas2015-10-09
| | | | | | | | | This flag has proven to be a recipe for bugs, and it doesn't seem like it can really buy anything in terms of performance. So let's just *always* set the process latch when we receive SIGUSR1 instead of trying to do it only when needed. Per my recent proposal on pgsql-hackers.
* Add recursion depth protections to regular expression matching.Tom Lane2015-10-02
| | | | | | | | | | | | | | | Some of the functions in regex compilation and execution recurse, and therefore could in principle be driven to stack overflow. The Tcl crew has seen this happen in practice in duptraverse(), though their fix was to put in a hard-wired limit on the number of recursive levels, which is not too appetizing --- fortunately, we have enough infrastructure to check the actually available stack. Greg Stark has also seen it in other places while fuzz testing on a machine with limited stack space. Let's put guards in to prevent crashes in all these places. Since the regex code would leak memory if we simply threw elog(ERROR), we have to introduce an API that checks for stack depth without throwing such an error. Fortunately that's not difficult.
* Determine whether it's safe to attempt a parallel plan for a query.Robert Haas2015-09-16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 924bcf4f16d54c55310b28f77686608684734f42 introduced a framework for parallel computation in PostgreSQL that makes most but not all built-in functions safe to execute in parallel mode. In order to have parallel query, we'll need to be able to determine whether that query contains functions (either built-in or user-defined) that cannot be safely executed in parallel mode. This requires those functions to be labeled, so this patch introduces an infrastructure for that. Some functions currently labeled as safe may need to be revised depending on how pending issues related to heavyweight locking under paralllelism are resolved. Parallel plans can't be used except for the case where the query will run to completion. If portal execution were suspended, the parallel mode restrictions would need to remain in effect during that time, but that might make other queries fail. Therefore, this patch introduces a framework that enables consideration of parallel plans only when it is known that the plan will be run to completion. This probably needs some refinement; for example, at bind time, we do not know whether a query run via the extended protocol will be execution to completion or run with a limited fetch count. Having the client indicate its intentions at bind time would constitute a wire protocol break. Some contexts in which parallel mode would be safe are not adjusted by this patch; the default is not to try parallel plans except from call sites that have been updated to say that such plans are OK. This commit doesn't introduce any parallel paths or plans; it just provides a way to determine whether they could potentially be used. I'm committing it on the theory that the remaining parallel sequential scan patches will also get committed to this release, hopefully in the not-too-distant future. Robert Haas and Amit Kapila. Reviewed (in earlier versions) by Noah Misch.
* Clean up icc + ia64 situation.Tom Lane2015-08-31
| | | | | | | | | | | | | | Some googling turned up multiple sources saying that older versions of icc do not accept gcc-compatible asm blocks on IA64, though asm does work on x86[_64]. This is apparently fixed as of icc version 12.0 or so, but that doesn't help us much; if we have to carry the extra implementation anyway, we may as well just use it for icc rather than add a compiler version test. Hence, revert commit 2c713d6ea29c91cd2cbd92fa801a61e55ea2a3c4 (though I separated the icc code from the gcc code completely, producing what seems cleaner code). Document the state of affairs more explicitly, both in s_lock.h and postgres.c, and make some cosmetic adjustments around the IA64 code in s_lock.h.
* Remove theoretically-unnecessary special case for icc.Tom Lane2015-08-31
| | | | | | | | Intel's icc is generally able to swallow asm blocks written for gcc. We have a few places that don't seem to know that, though. Experiment with removing the special case for icc in ia64_get_bsp(); if the buildfarm likes this, I'll try more cleanup. This is a good test case because it involves a "stop" notation that seems like it might not be very portable.
* pgindent run for 9.5Bruce Momjian2015-05-23
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* Create an infrastructure for parallel computation in PostgreSQL.Robert Haas2015-04-30
| | | | | | | | | | | | | | | | | This does four basic things. First, it provides convenience routines to coordinate the startup and shutdown of parallel workers. Second, it synchronizes various pieces of state (e.g. GUCs, combo CID mappings, transaction snapshot) from the parallel group leader to the worker processes. Third, it prohibits various operations that would result in unsafe changes to that state while parallelism is active. Finally, it propagates events that would result in an ErrorResponse, NoticeResponse, or NotifyResponse message being sent to the client from the parallel workers back to the master, from which they can then be sent on to the client. Robert Haas, Amit Kapila, Noah Misch, Rushabh Lathia, Jeevan Chalke. Suggestions and review from Andres Freund, Heikki Linnakangas, Noah Misch, Simon Riggs, Euler Taveira, and Jim Nasby.
* Use FLEXIBLE_ARRAY_MEMBER in a bunch more places.Tom Lane2015-02-20
| | | | | | | | | | | | | | | | Replace some bogus "x[1]" declarations with "x[FLEXIBLE_ARRAY_MEMBER]". Aside from being more self-documenting, this should help prevent bogus warnings from static code analyzers and perhaps compiler misoptimizations. This patch is just a down payment on eliminating the whole problem, but it gets rid of a lot of easy-to-fix cases. Note that the main problem with doing this is that one must no longer rely on computing sizeof(the containing struct), since the result would be compiler-dependent. Instead use offsetof(struct, lastfield). Autoconf also warns against spelling that offsetof(struct, lastfield[0]). Michael Paquier, review and additional fixes by me.
* Remove ill-conceived Assertion in ProcessClientWriteInterrupt().Andres Freund2015-02-03
| | | | | | | | | | | | It's perfectly fine to have blocked interrupts when ProcessClientWriteInterrupt() is called. In fact it's commonly the case when emitting error reports. And we deal with that correctly. Even if that'd not be the case, it'd be a bad location for such a assertion. Because ProcessClientWriteInterrupt() is only called when the socket is blocked it's hard to hit. Per Heikki and buildfarm animals nightjar and dunlin.
* Remove remnants of ImmediateInterruptOK handling.Andres Freund2015-02-03
| | | | | | | Now that nothing sets ImmediateInterruptOK to true anymore, we can remove all the supporting code. Reviewed-By: Heikki Linnakangas
* Don't allow immediate interrupts during authentication anymore.Andres Freund2015-02-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | We used to handle authentication_timeout by setting ImmediateInterruptOK to true during large parts of the authentication phase of a new connection. While that happens to work acceptably in practice, it's not particularly nice and has ugly corner cases. Previous commits converted the FE/BE communication to use latches and implemented support for interrupt handling during both send/recv. Building on top of that work we can get rid of ImmediateInterruptOK during authentication, by immediately treating timeouts during authentication as a reason to die. As die interrupts are handled immediately during client communication that provides a sensibly quick reaction time to authentication timeout. Additionally add a few CHECK_FOR_INTERRUPTS() to some more complex authentication methods. More could be added, but this already should provides a reasonable coverage. While it this overall increases the maximum time till a timeout is reacted to, it greatly reduces complexity and increases reliability. That seems like a overall win. If the increase proves to be noticeable we can deal with those cases by moving to nonblocking network code and add interrupt checking there. Reviewed-By: Heikki Linnakangas
* Process 'die' interrupts while reading/writing from the client socket.Andres Freund2015-02-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Up to now it was impossible to terminate a backend that was trying to send/recv data to/from the client when the socket's buffer was already full/empty. While the send/recv calls itself might have gotten interrupted by signals on some platforms, we just immediately retried. That could lead to situations where a backend couldn't be terminated , after a client died without the connection being closed, because it was blocked in send/recv. The problem was far more likely to be hit when sending data than when reading. That's because while reading a command from the client, and during authentication, we processed interrupts immediately . That primarily left COPY FROM STDIN as being problematic for recv. Change things so that that we process 'die' events immediately when the appropriate signal arrives. We can't sensibly react to query cancels at that point, because we might loose sync with the client as we could be in the middle of writing a message. We don't interrupt writes if the write buffer isn't full, as indicated by write() returning EWOULDBLOCK, as that would lead to fewer error messages reaching clients. Per discussion with Kyotaro HORIGUCHI and Heikki Linnakangas Discussion: 20140927191243.GD5423@alap3.anarazel.de
* Introduce and use infrastructure for interrupt processing during client reads.Andres Freund2015-02-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Up to now large swathes of backend code ran inside signal handlers while reading commands from the client, to allow for speedy reaction to asynchronous events. Most prominently shared invalidation and NOTIFY handling. That means that complex code like the starting/stopping of transactions is run in signal handlers... The required code was fragile and verbose, and is likely to contain bugs. That approach also severely limited what could be done while communicating with the client. As the read might be from within openssl it wasn't safely possible to trigger an error, e.g. to cancel a backend in idle-in-transaction state. We did that in some cases, namely fatal errors, nonetheless. Now that FE/BE communication in the backend employs non-blocking sockets and latches to block, we can quite simply interrupt reads from signal handlers by setting the latch. That allows us to signal an interrupted read, which is supposed to be retried after returning from within the ssl library. As signal handlers now only need to set the latch to guarantee timely interrupt processing, remove a fair amount of complicated & fragile code from async.c and sinval.c. We could now actually start to process some kinds of interrupts, like sinval ones, more often that before, but that seems better done separately. This work will hopefully allow to handle cases like being blocked by sending data, interrupting idle transactions and similar to be implemented without too much effort. In addition to allowing getting rid of ImmediateInterruptOK, that is. Author: Andres Freund Reviewed-By: Heikki Linnakangas
* Add new function BackgroundWorkerInitializeConnectionByOid.Robert Haas2015-02-02
| | | | | | Sometimes it's useful for a background worker to be able to initialize its database connection by OID rather than by name, so provide a way to do that.
* Be more careful to not lose sync in the FE/BE protocol.Heikki Linnakangas2015-02-02
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If any error occurred while we were in the middle of reading a protocol message from the client, we could lose sync, and incorrectly try to interpret a part of another message as a new protocol message. That will usually lead to an "invalid frontend message" error that terminates the connection. However, this is a security issue because an attacker might be able to deliberately cause an error, inject a Query message in what's supposed to be just user data, and have the server execute it. We were quite careful to not have CHECK_FOR_INTERRUPTS() calls or other operations that could ereport(ERROR) in the middle of processing a message, but a query cancel interrupt or statement timeout could nevertheless cause it to happen. Also, the V2 fastpath and COPY handling were not so careful. It's very difficult to recover in the V2 COPY protocol, so we will just terminate the connection on error. In practice, that's what happened previously anyway, as we lost protocol sync. To fix, add a new variable in pqcomm.c, PqCommReadingMsg, that is set whenever we're in the middle of reading a message. When it's set, we cannot safely ERROR out and continue running, because we might've read only part of a message. PqCommReadingMsg acts somewhat similarly to critical sections in that if an error occurs while it's set, the error handler will force the connection to be terminated, as if the error was FATAL. It's not implemented by promoting ERROR to FATAL in elog.c, like ERROR is promoted to PANIC in critical sections, because we want to be able to use PG_TRY/CATCH to recover and regain protocol sync. pq_getmessage() takes advantage of that to prevent an OOM error from terminating the connection. To prevent unnecessary connection terminations, add a holdoff mechanism similar to HOLD/RESUME_INTERRUPTS() that can be used hold off query cancel interrupts, but still allow die interrupts. The rules on which interrupts are processed when are now a bit more complicated, so refactor ProcessInterrupts() and the calls to it in signal handlers so that the signal handlers always call it if ImmediateInterruptOK is set, and ProcessInterrupts() can decide to not do anything if the other conditions are not met. Reported by Emil Lenngren. Patch reviewed by Noah Misch and Andres Freund. Backpatch to all supported versions. Security: CVE-2015-0244
* Add a default local latch for use in signal handlers.Andres Freund2015-01-14
| | | | | | | | | | | | | | | | | | | | To do so, move InitializeLatchSupport() into the new common process initialization functions, and add a new global variable MyLatch. MyLatch is usable as soon InitPostmasterChild() has been called (i.e. very early during startup). Initially it points to a process local latch that exists in all processes. InitProcess/InitAuxiliaryProcess then replaces that local latch with PGPROC->procLatch. During shutdown the reverse happens. This is primarily advantageous for two reasons: For one it simplifies dealing with the shared process latch, especially in signal handlers, because instead of having to check for MyProc, MyLatch can be used unconditionally. For another, a later patch that makes FEs/BE communication use latches, now can rely on the existence of a latch, even before having gone through InitProcess. Discussion: 20140927191243.GD5423@alap3.anarazel.de
* Commonalize process startup code.Andres Freund2015-01-14
| | | | | | | | | Move common code, that was duplicated in every postmaster child/every standalone process, into two functions in miscinit.c. Not only does that already result in a fair amount of net code reduction but it also makes it much easier to remove more duplication in the future. The prime motivation wasn't code deduplication though, but easier addition of new common code.
* Update copyright for 2015Bruce Momjian2015-01-06
| | | | Backpatch certain files through 9.0
* Explicitly support the case that a plancache's raw_parse_tree is NULL.Tom Lane2014-11-12
| | | | | | | | | | | | | | | | | | | | | | | This only happens if a client issues a Parse message with an empty query string, which is a bit odd; but since it is explicitly called out as legal by our FE/BE protocol spec, we'd probably better continue to allow it. Fix by adding tests everywhere that the raw_parse_tree field is passed to functions that don't or shouldn't accept NULL. Also make it clear in the relevant comments that NULL is an expected case. This reverts commits a73c9dbab0165b3395dfe8a44a7dfd16166963c4 and 2e9650cbcff8c8fb0d9ef807c73a44f241822eee, which fixed specific crash symptoms by hacking things at what now seems to be the wrong end, ie the callee functions. Making the callees allow NULL is superficially more robust, but it's not always true that there is a defensible thing for the callee to do in such cases. The caller has more context and is better able to decide what the empty-query case ought to do. Per followup discussion of bug #11335. Back-patch to 9.2. The code before that is sufficiently different that it would require development of a separate patch, which doesn't seem worthwhile for what is believed to be an essentially cosmetic change.
* Invent PGC_SU_BACKEND and mark log_connections/log_disconnections that way.Tom Lane2014-09-13
| | | | | | | | | | | | | | | | | | | This new GUC context option allows GUC parameters to have the combined properties of PGC_BACKEND and PGC_SUSET, ie, they don't change after session start and non-superusers can't change them. This is a more appropriate choice for log_connections and log_disconnections than their previous context of PGC_BACKEND, because we don't want non-superusers to be able to affect whether their sessions get logged. Note: the behavior for log_connections is still a bit odd, in that when a superuser attempts to set it from PGOPTIONS, the setting takes effect but it's too late to enable or suppress connection startup logging. It's debatable whether that's worth fixing, and in any case there is a reasonable argument for PGC_SU_BACKEND to exist. In passing, re-pgindent the files touched by this commit. Fujii Masao, reviewed by Joe Conway and Amit Kapila
* Fix typos in comments.Fujii Masao2014-07-07
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